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Pilot/Controller Glossary

3/29/18

PCG P−3

PRECISION APPROACH RADAR− Radar equip-

ment in some ATC facilities operated by the FAA

and/or the military services at joint-use civil/military

locations and separate military installations to detect

and display azimuth, elevation, and range of aircraft

on the final approach course to a runway. This

equipment may be used to monitor certain non−radar

approaches, but is primarily used to conduct a

precision instrument approach (PAR) wherein the

controller issues guidance instructions to the pilot

based on the aircraft’s position in relation to the final

approach course (azimuth), the glidepath (elevation),

and the distance (range) from the touchdown point on

the runway as displayed on the radar scope.

Note: The abbreviation “PAR” is also used to

denote preferential arrival routes in ARTCC

computers.

(See GLIDEPATH.)
(See PAR.)
(See PREFERENTIAL ROUTES.)
(See ICAO term PRECISION APPROACH

RADAR.)

(Refer to AIM.)

PRECISION APPROACH RADAR [ICAO]− Pri-

mary radar equipment used to determine the position

of an aircraft during final approach, in terms of lateral

and vertical deviations relative to a nominal approach

path, and in range relative to touchdown.

Note: Precision approach radars are designed to

enable pilots of aircraft to be given guidance by

radio communication during the final stages of the

approach to land.

PRECISION OBSTACLE FREE ZONE (POFZ)−

An 800 foot wide by 200 foot long area centered on

the runway centerline adjacent to the threshold

designed to protect aircraft flying precision

approaches from ground vehicles and other aircraft

when ceiling is less than 250 feet or visibility is less

than 3/4 statute mile (or runway visual range below

4,000 feet.)

PRECISION RUNWAY MONITOR (PRM)

SYSTEM− Provides air  traffic controllers

monitoring the NTZ during simultaneous close

parallel PRM approaches with precision, high update

rate secondary surveillance data. The high update rate

surveillance sensor component of the PRM system is

only required for specific runway or approach course

separation. The high resolution color monitoring

display, Final Monitor Aid (FMA) of the PRM

system, or other FMA with the same capability,

presents NTZ surveillance track data to controllers

along with detailed maps depicting approaches and

no transgression zone and is required for all

simultaneous close parallel PRM NTZ monitoring

operations.

(Refer to AIM)

PREDICTIVE WIND SHEAR ALERT SYSTEM

(PWS)− A self−contained system used on board some

aircraft to alert the flight crew to the presence of a

potential wind shear. PWS systems typically monitor

3 miles ahead and 25 degrees left and right of the

aircraft’s heading at or below 1200’ AGL. Departing

flights may receive a wind shear alert after they start

the takeoff roll and may elect to abort the takeoff.

Aircraft on approach receiving an alert may elect to

go around or perform a wind shear escape maneuver.
PREFERENTIAL ROUTES− Preferential routes

(PDRs, PARs, and PDARs) are adapted in ARTCC

computers to accomplish inter/intrafacility controller

coordination and to assure that flight data is posted at

the proper control positions. Locations having a need

for these specific inbound and outbound routes

normally publish such routes in local facility

bulletins, and their use by pilots minimizes flight

plan route amendments. When the workload or traffic

situation permits, controllers normally provide radar

vectors or assign requested routes to minimize

circuitous routing. Preferential routes are usually

confined to one ARTCC’s area and are referred to by

the following names or acronyms:

a. Preferential Departure Route (PDR). A specific

departure route from an airport or terminal area to an

en route point where there is no further need for flow

control. It may be included in an Instrument

Departure Procedure (DP) or a Preferred IFR Route.

b. Preferential Arrival Route (PAR). A specific

arrival route from an appropriate en route point to an

airport or terminal area. It may be included in a

Standard Terminal Arrival (STAR) or a Preferred IFR

Route. The abbreviation “PAR” is used primarily

within the ARTCC and should not be confused with

the abbreviation for Precision Approach Radar.

c. Preferential Departure and Arrival Route

(PDAR). A route between two terminals which are

within or immediately adjacent to one ARTCC’s area.

PDARs are not synonymous with Preferred IFR

Routes but may be listed as such as they do

accomplish essentially the same purpose.

(See PREFERRED IFR ROUTES.)